Machine with a coolable winding arranged in a winding support and with a torque transmitting device

ABSTRACT

The machine comprises a rotor with a winding for cooling, which is in particular superconducting, in a winding support. A device with a composite body made of fiber-reinforced plastic is provided, for retention of the winding support within a rotor outer housing, on a torque transmitting side. The composite body is in one piece and comprises lateral pieces and a center piece, whereby the lateral pieces extend outwards in a funnel shape and the center piece is in the form of a hollow cylinder. The lateral pieces should at least partly comprises a corrugated form in the circumferential direction and are connected with a positive or friction fit by press-ring bodies with flange-like fixing pieces made from metal.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and hereby claims priority to PCTApplication No. PCT/DE2003/002446 filed Jul. 21, 2003 and GermanApplication No. 102 35 503.7 filed Aug. 2, 2002, the contents of whichare hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The invention relates to a machine having a rotor which is mounted suchthat it can rotate about a rotation axis and has a rotor externalhousing which is attached to rotor shaft parts and surrounds a windingformer with a winding that is to be cooled, in particular asuperconductive winding. The rotor also has a device to hold the windingformer within the rotor external housing, which device comprises, atleast at one end of the winding former, a device which transmits torquebetween the winding former and the associated rotor shaft part with atleast one rotationally symmetrical composite body composed of a plasticreinforced with fiber material. A corresponding machine is disclosed inU.S. Pat. No. 5,880,547 A.

Special types of electrical machines, in particular generators ormotors, have a rotating field winding and a stationary stator winding.In this case, the current density and thus the specific power of themachine, that is to say the power per kilogram of its own weight; can beincreased, and the efficiency of the machine can also be increased, bythe use of cryogenically cooled and in particular superconductiveconductors.

Cryogenically cooled windings of electrical machines generally have tobe thermally isolated from the environment and have to be kept at therequired low temperature by a coolant. Effective thermal isolation canin this case be achieved only by the cryogenically cooled parts of themachine being separated as far as possible from the warm external areaby a vacuum with a residual gas pressure of generally less than 10⁻³mbar, and by the connecting parts between these cryogenically cooledparts and the warm external area transmitting as little heat aspossible. Two variants, in particular, are known for vacuum isolation ofrotors with rotor windings which have to be cryogenically cooled andwith warm stator windings:

In a first embodiment, the rotor has a warm external housing and anencapsulated vacuum area which rotates with the rotor. The vacuum areashould in this case surround the cryogenically cooled area on all sides(see, for example, “Siemens Forsch. u. Entwickl.-Ber. [Siemens Researchand Development Reports]”, Vol. 5, 1976, No. 1, pages 10 to 16).However, heat is transferred undesirably to the cryogenically cooledparts via the supports which extend through the vacuum area.

In a second embodiment, the essentially cold rotor rotates in a hardvacuum. In this case, the outer boundary of the hard vacuum area isdefined by the internal bore of the stator. However, an arrangement suchas this requires shaft seals which can resist a hard vacuum between therotor and the stator (see, for example, DE 27 53 461 A).

The first-mentioned variant is provided in the machine which can befound in the cited US-A specification. Accordingly, a superconductivewinding for its rotor is located in the interior of a rotor cryostatwhich, together with flanged shafts that are fitted, forms an externalhousing for the rotor. Helium cooling is provided for the windingsuperconductors. In contrast, the external contour of the rotor externalhousing is approximately at room temperature, or even above roomtemperature during operation. The useful torque from the machine isproduced in the rotor winding. This rotor winding is arranged in a coldwinding former which is itself suspended and held in an isolated form inthe rotor external housing, which acts as a cryostat. In this case, thissuspension or retention on the drive end of the rotor, which isfrequently also referred to as the A side of the machine, must besufficiently robust to transmit the torque from the cold winding formerto a warmer shaft part on the drive end. A corresponding, rigidconnecting device for torque transmission therefore has to be designedto be relatively massive and must be connected to the winding former andto the shaft part on the drive end such that power can be transmitted.This means that heat is unavoidably introduced into the cold area of therotor. It is therefore frequently necessary to cool the connectingdevice which transmits the torque (see, for example, “Handbook ofApplied Superconductivity”, Vol. 2: Ed.: B. Seeber, Institute of PhysicsPublishing, Bristol (GB), 1998, pages 1497 to 1499 and 1522 to 1530). Atthe same time, this connecting device also provides the drive-sidecentering for the cold winding former. Virtually no torque is emitted onthe opposite rotor side, which is also referred to as the non-drive endor in general as the B side, where important connections, such as acoolant supply, are provided for operation of the machine. Only thefunctions of centering and thermal isolation therefore, essentially,have to be carried out here. Furthermore, measures to compensate forshrinkage of the cooled winding former are planned there.

In order to reduce the amount of heat which is introduced into thecooled superconductive area of the rotor, one specific embodiment of themachine that is disclosed in the cited US-A specification provides forthe connecting device which transmits the torque to have, at least onthe drive end, a hollow-cylindrical composite body composed of aglass-fiber-reinforced plastic. This hollow cylinder is provided at eachof its two axle ends with a steel attachment part, which is connected tothe winding former and to the drive shaft such that power can betransmitted. The mechanical connection between the plastic hollowcylinder and the steel attachment parts has to ensure good resistance tooverloads and a long fatigue life when subjected to alternating loads,since, for example during starting and in various fault situations onmotors such as these, considerably higher torques than those duringnormal operation occur and must not lead to damage to the device whichtransmits the torque. However, the US-A specification does not containany details relating to this.

Such details are addressed in U.S. Pat. No. 6,129,477 A. In this case, aconically running surface is used to transmit torque between the variousparts of this device, which are composed of materials with differentshearing moduli via a connecting device, with the intention of bondingoccurring between these parts on this surface. A first part of theconnecting device is in this case composed of a glass-fiber-reinforcedplastic, while a second part is made of metal. In this case as well, thefunctionality of the torque transmission depends to a major extent onthe fatigue life of the bond between these parts.

In addition to metallic superconductor materials such as NbTi or Nb₃Snwhich have been known for a long time and as are used in the machinesmentioned above, metal-oxide superconductor materials with criticaltemperatures above 77 K have also been known since 1987. Attempts havebeen made to use conductors based on such high-T_(c) superconductormaterials, which are also referred to as HTC materials, to producesuperconductive windings for machines (see, for example, WO 98/02953 A).Owing to the temperature differences between the operating temperatureof the superconductor material and the external temperature on thewarmer rotor external housing, even machines of this conductor typerequire measures to reduce the temperature that is introduced into thesuperconductive area.

SUMMARY OF THE INVENTION

One potential object is to refine the machine having the featuresmentioned initially such that its connecting device for torquetransmission makes it possible to provide a connection which cantransmit power and ensures a long fatigue life and good resistance tooverloading between the cold winding former and the associated warmrotor shaft part, while at the same time limiting the losses resultingfrom heat being introduced into the cold winding former.

Accordingly, in the case of the machine having the features quoted inthe introduction, the composite body of the device which transmitstorque should integrally contain side parts and a center part locatedbetween them, with the side part being formed at least in one subsectionsuch that it widens towards the exterior in the form of a funnel, andwith a center part being formed as a hollow cylinder, and with the sideparts, at least in one subsection having a corrugated shape when seen inthe circumferential direction, while the center part is at least largelyuncorrugated. In this case, the composite body should be connected onits side parts to flange-like attachment points composed of metal, inthat at least each side part of the composite body can be pressedagainst a mating surface whose shape is matched to it, by a compressionring body, which can be connected to the respective attachment part in aforce-fitting manner and has a pressing surface whose shape is matchedto it, with at least a section of the center part of the composite bodybeing left free.

The advantages associated with this refinement of the machine are thatthe particular refinement of the rotationally symmetrical fibercomposite body at least in the area of its end side parts, and thecorresponding design of the flange-like attachment parts in theconnecting area to these side parts results in a good interlockingconnection, which can transmit power, between the poorly thermallyconductive part of the composite body and the metal parts of the windingformer. This advantageously avoids problems relating to the shearstrength, in particular with respect to overload and during continuousoperation, in the connecting area between the plastic and metal, andwhich otherwise represents a weak point for torque transmission, in thatthe torque is now transmitted primarily by pressure or a pressing forceand less by shear, by matched corrugation to the parts which rest on oneanother in an interlocking manner.

If required, the power transmission can be improved by coating, inparticular, the corrugated surfaces of the fiber composite body with asuitable adhesive resin, which may be filled or unfilled, beforeinstallation in order to prevent cavities from appearing during thepressing process. Such pressing and the matched corrugation do not justprevent the fiber composite body from sliding with respect to theattachment parts; in fact, this also improves the power transmission bycompression forces instead of by shear forces in the “metal-plastic”connecting area.

Thus, in particular, the side parts are provided with a corrugated shapewhich is distributed uniformly over the circumference. In this case, thecorrugated shape may preferably be sinusoidal or in the form of acircular arc. A refinement of the side parts such as this and of thosesurfaces of the compression ring body and of the attachment elementswhich rest on them in an interlocking manner makes it possible to ensurethat power is transmitted particularly uniformly between these parts.The corrugation of the side parts in this case may be implemented onlyin one subsection in each case.

It can be regarded as being particularly advantageous for the centerpart of the fiber composite body to be pressed against a correspondingpart of the respective mating surface in an interlocking manner suchthat power can be transmitted in the side junction areas to therespective side part from the respective compression ring body. Thisavoids particular loading in the junction areas between the corrugatedside parts and the uncorrugated center part. The uncorrugatedconfiguration of the remaining center part in this case advantageouslyassists in the reduction of the risk of this part buckling.

Furthermore, it is particularly advantageous for at least the majority(that is to say more than half) of the fibers of the fiber material toextend without interruption at least over the junction area between thecenter part of the composite body and the respective side part. This isbecause fibers which are continuous over these areas contribute to theseintrinsically critical areas having a high power loading capability.Known fiber materials, in particular glass fibers or carbon fibers, maybe used as the fibers.

In order to improve the power transmission and to achieve good torquetransmission between the flange-like attachment elements and the windingformer or the drive-side housing or rotor shaft part, the attachmentelements are advantageously provided with an end tooth system, whichengages in a corresponding tooth system on the respective mating piece.The tooth system may in this case be designed to be self-locking.Appropriate tooth systems are known per se.

Either metallic low-T_(c) superconductor material or, in particular,metal-oxide high-T_(c) superconductor material may be used for theconductors for the winding to be cooled. The use of the last-mentionedmaterial simplifies the cooling technique.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the present invention willbecome more apparent and more readily appreciated from the followingdescription of the preferred embodiments, taken in conjunction with theaccompanying drawings of which:

FIG. 1 shows a longitudinal section through one possible embodiment ofthe machine,

FIG. 2 shows a longitudinal section through a first specific refinementof a connecting device which transmits torque for this machine,

FIG. 3 shows a plan view of a cross section through this connectingdevice as shown in FIG. 2,

FIG. 4 shows a longitudinal section through the fiber composite body ofthis connecting device,

FIG. 5 shows a cross section through this fiber composite body in thearea of a side part,

FIGS. 6 and 7 respectively show a longitudinal section and a crosssection through a further embodiment of a connecting device whichtransmits torque, corresponding to the illustration in FIGS. 2 and 3,and

FIG. 8 shows a front view of a flange-like attachment element for theconnecting device shown in FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout.

Corresponding parts are provided with the same reference symbols in thefigures.

The embodiment of the machine as described in the following text may, inparticular, be a synchronous motor or a generator. Other fields ofapplication or use of corresponding machines, for example for highrotation speeds, compact drives, for example for marine vessels or forso-called off-shore facilities such as drilling platforms are, ofcourse, also possible. The machine has a rotating, normally conductiveor superconductive rotor winding, which in principle allows use ofmetallic low-T_(c) superconductor material or, in particular, oxidehigh-T_(c) superconductor material. The winding may be in the form of acoil or a system of coils based on a two-pole, four-pole or othermultiple pole arrangement. The fundamental design of a synchronousmachine such as this is shown in FIG. 1, based on known embodiments ofmachines such as these (see the cited publications).

The machine, which is annotated in general by 2, has a stationarymachine external housing 3 which is at room temperature and has a statorwinding 4 in it. A rotor 5 is held within this external housing andsurrounded by the stator winding 4, in bearings 6 a and 6 b such that itcan rotate about a rotation axis RA. For this purpose, the rotor has arotor external housing 7 which is in the form of a vacuum vessel and inwhich a winding former 9 with a winding 10 that is to be cooled, forexample an HTC winding, is held. On each of its axially opposite (end)faces, this rotor external housing has a housing part 7 a or 7 b whichis in the form of a disk or annular disk. Each of these housing parts isrespectively rigidly connected to an axial rotor shaft part 5 a or 5 b,with each rotor shaft part being associated with a respective one of thebearings 6 a or 6 b. A rigid, rotationally symmetrical device 8 a isprovided on the so-called drive end A of the rotor external housing 7,between the winding former and the housing part 7 a, which is in theform of a disk and is firmly connected to the rotor shaft part 5 a. Inparticular, the torque is also transmitted via this device, which isdesigned and is referred to in the following text as a connecting device8 a, by flange-like attachment parts 12 a and 12 b at the ends and afiber composite body 13 which runs inbetween them (see, in particular,FIGS. 2 and 3). This composite body is advantageously essentially in theform of a poorly thermally conductive hollow cylinder composed of aplastic material reinforced with fibers such as glass fibers (so-called“GFC” material). In this case, the fibers are placed in a manner knownper se in the plastic material, which is used as a matrix for them andis selected on the basis of strength considerations, preferably over theentire axial extent. The fibers in this case preferably run obliquelywith respect to the rotation axis RA in the plastic material, that is tosay not parallel or at right angles to it. If required, they may also bein different layers, in which case their angles with respect to the axismay also differ. The composite material formed in this way then ensuressufficiently good mechanical stiffness for torque transmission and ahigh shear modulus (G modulus) with low thermal conductivity at the sametime. Further details of the connecting device which transmits torqueare illustrated in particular in FIGS. 2 to 5.

As is also evident from FIG. 1, a further connecting device 8 b isarranged between the winding former 9 and the side housing part 7 b(which is in the form of a disk) of the rotor external housing 7 at thenon-drive end, which is opposite the drive end A and is referred to inthe following text as B. Inter alia, a coolant supply for cooling the(in particular) superconductive winding 10 from outside the machine isprovided via the hollow-cylindrical shaft part 5 b at this end B.Details of the coolant supply and of the seal are known. These partshave therefore not been illustrated in detail in the figure. A vacuumwhich surrounds the winding former 9 together with the winding 10 to becooled is annotated V. The vacuum exists, in particular, between thewarm rotor external housing 7 and the cold winding former 9. Theillustration does not show known measures for thermal isolation, such assuperisolation.

GFC parts are advantageously used to reduce the amount of heatintroduced from the side housing parts 7 a and 7 b (which are at roomtemperature and are thus warmer) of the rotor external housing into thecold part (which is at low temperature) of the winding former 9, andthus into the cold winding 10. The longitudinal section in FIG. 2 showsone specific embodiment of a connecting device 8 a designed at the driveend A. The connecting device 8 b at the non-drive end B may havecorresponding features. Furthermore, the latter device should bedesigned so as to allow axial expansion compensation owing to shrinkagesof the cooled rotor parts.

In addition to the requirement to minimize the heat transmission, itmust also, in particular, be possible to transmit high machine torquesbetween the GFC fiber composite body 13 and the metal flange-likeattachment parts 12 a and 12 b. For this purpose, the fiber compositebody 13, which is rotationally symmetrical and surrounds the axis RA, iscomposed of at least three parts, specifically a hollow-cylindricalcenter part 13 c as well as two side parts 13 a and 13 b which widenaxially outwards in the form of a funnel from the radius of the centerpart to larger radii (in this context, see also FIG. 4). In this case, asingle subsection of these side parts could in each case be structured,as a departure from a smooth, uncorrugated funnel shape, so as toresult, when seen in the circumferential direction, in a regularcorrugation with projections 17 j and depressions 18 j. The corrugatedshape is shown in more detail in the side cross-sectional view in FIG. 3and, in particular, in the cross section shown in FIG. 5. Suchcorrugation can preferably be stamped by appropriate shaping tools whilethe fiber composite body is still in a state in which it can be deformedduring production, during which process the fiber reinforcement isadvantageously not damaged, so that the mechanical robustness of thecomposite material is maintained. The fiber composite body 13 togetherwith its center part 13 c and its end face parts 13 a and 13 b are thusformed integrally. The corrugation of the side parts on which thefigures are based is preferably sinusoidal and, in particular, isdistributed uniformly over the entire circumference, for good torquetransmission. If required, however, other corrugation shapes, such ascircular arc shapes, may also be provided, and the circumference alsoneed be provided with such corrugation only in individual areas. Incontrast, the center part 13 c could at least largely be uncorrugated.

In order to ensure an interlock between the side parts 13 a and 13 bthat have been corrugated in this way and the respective attachment part12 a or 12 b, the mating surfaces 14 a and 14 b of the respectiveattachment parts should have a corrugation matching the corrugation onthe associated side parts. A compression ring body 15 a and 15 b,respectively, is in each case provided in order to ensure that the sideparts 13 a and 13 b are firmly seated on these mating surfaces 14 a and14 b, as can also be seen from FIG. 2. These compression ring bodies arelikewise corrugated on their respective pressing surfaces 19 a and 19 b,which rest on the respective side part, with this corrugation beingmatched to the corrugation on the side of the respective side partfacing away from the mating surface. In the exemplary embodiment shownin FIG. 2, the compression bodies 15 a and 15 b can be screwed to therespective attachment parts 12 a and 12 b by screw connections 20 a and20 b such that the side parts are firmly pressed against the associatedmating surfaces such that power can be transmitted. If required, beforeinstallation, the fiber composite body 13 may also be coated with asuitable filled or unfilled adhesive resin on the side parts for betterpower transmission, in order to ensure that no cavities are producedduring the pressing process. If the metal surfaces of the attachmentparts are treated with a separating mechanism, the structure can alsoadvantageously be disassembled in the event of a defect in the fibercomposite body. The machine is now provided with interlocking,power-transmitting compression instead of the previously normal, purelyknown bonding technique for the connection between the metal and thefiber composite material.

As can also be seen from FIG. 2, the attachment elements 12 a and 12 band the compression ring bodies 15 a and 15 b do not just surround theside parts 13 a and 13 b of the fiber composite body 13, but also extendsomewhat over the center part 13 c. The distance a to be kept free inparticular between the compression ring bodies 15 a and 15 b, that is tosay without any touching metallic parts, is in this case defined on theone hand with regard to strength aspects and on the other hand withregard to the heat transmission being as low as possible. This makes itpossible to prevent particularly powerful loads in the junction areafrom the corrugated side parts to the uncorrugated center part.

Effective torque transmission between the metallic attachment parts 12 aand 12 b and the non-metallic fiber composite body 13 can thus beensured without any risk of damage in the connecting areas between theseparts when high torsional forces occur. Furthermore, this at the sametime forms a precautionary measure against the possibility of cracksbeing formed on edges.

Other refinements of the side parts 13 a and 13 b of the fiber compositebody 13 and thus of the associated mating surfaces of the respectiveattachment element 12 a, 12 b and of the compression ring bodies 15 a,15 b are, of course, also possible, provided that projections anddepressions (which engage in one another and are distributed regularlyin this direction) on the parts to be connected preclude rotation withrespect to one another in the circumferential direction, and ensure therequired torque transmission. These requirements can be satisfied inparticular by the corrugation illustrated in FIGS. 2 and 3. However,other structures which engage in one another, such as tooth systems, arealso feasible. Other structures such as these are also intended to becovered by the expression “corrugation” (or “corrugated”) for therefinement of the fiber composite body and of the parts associated withit.

FIGS. 6 and 7 respectively show a longitudinal section and a crosssection, illustrated in a form corresponding to FIGS. 2 and 3, of afurther exemplary embodiment of a fiber composite body 23 such as thisin a connecting device 21 a. The device 21 a differs from the connectingdevice 8 a shown in FIG. 2 essentially by a particular shape of itsfiber composite body 23 between the metal attachment parts 22 a and 22b. Like the fiber composite body 13, the fiber composite body 23 has atubular, uncorrugated center part 23 c. However, its side parts 23 a and23 b are specially shaped. Specifically, these side parts 23 a and 23 bare each composed of two respective subsections 23 a ₁, 23 a ₂ and 23 b₁, 23 b ₂, with the subsections 23 a ₁ and 23 b ₁ which are adjacent tothe center part 23 c each being in the form of a funnel which widensoutwards, and the subsections 23 a ₂ and 23 b ₂ forminghollow-cylindrical end parts which extend outwards parallel to the axis.At least one of the two subsections of each side part is once againcorrugated. A corrugated shape can thus be provided, for example, onlyfor the end parts 23 a ₂ and 23 b ₂, as assumed for the exemplaryembodiment. However, it is also possible, in addition to this or insteadof it, to include a corrugated shape for the funnel-shaped subsections23 a ₁ and 23 b ₁ as shown in FIG. 2. In order to install the connectingdevice 21 a, corrugated end parts 23 a ₂ and 23 b ₂ are inserted intocorrespondingly milled grooves in the respective flange-like attachmentpart 22 a or 22 b, with their respective funnel-shaped subsections 23 a₁ and 23 b ₁ resting on a respective mating surface 26 a or 26 b, with amatched shape, on the associated attachment part. The power transmittingconnection between these parts is once again provided by compressionring bodies 15 a and 15 b, whose pressing surfaces 19 a and 19 b pressthe fiber composite body 23 against the mating surfaces 26 a and 26 b ofthe respective attachment part 22 a or 22 b. In this embodiment, eachcompression ring body and the associated mating surfaces may, of course,also extend somewhat over the tubular center part (without corrugation).

In order to transmit high torques between the flange-like attachmentparts 12 a and 12 b or 22 a and 22 b on the one hand and the windingformer 9 or the drive-end housing part 7 a on the other hand, therespective flange-like attachment part is advantageously not justscrewed to the winding former 9 or to the housing part 7 a. In fact, asis indicated by the illustration of the attachment part 12 a chosen forFIG. 8, each attachment part may advantageously have an end tooth system29, which can be seen in the side view in the figure, with projectingteeth 29 a and groove-like intermediate spaces or depressions 29 bbetween them. In this case, the tooth system can advantageously bedesigned in a manner known per se so as to produce a self-centeringconnection which can transmit power, and in which case the torque can bepassed on over a relatively large radius. The mating surface of thewinding former 9 or of the housing part 7 a has a corresponding toothsystem, with the teeth 29 a in the tooth system 29 on the flange-likeattachment part 12 a engaging in corresponding grooves in the matingsurface of the winding former or of the housing part. The figure alsoshows holes 30 i for a screw connection between the attachment part 12 aand the winding former 9.

The exemplary embodiments that have been explained above have been basedon the assumption that a glass-fiber-reinforced plastic (GFC) is usedfor the fiber composite bodies 13 and 23. It is, of course, alsopossible to use plastics reinforced with other fibers, for example withcarbon fibers, provided that these materials ensure torque transmissionwith poor heat transmission at the same time.

Furthermore, a connecting device designed may also have a plurality ofconcentrically surrounding composite bodies rather than a singlehollow-cylindrical fiber composite body, each, if required, also havingtheir own flange-like, concentrically surrounding attachment parts.

Furthermore, the exemplary embodiments illustrated in the figures havebeen based on the assumption that the mating surfaces against which therespective composite body is pressed by a plurality of compression ringbodies, which may also be formed by just a single component, are formedon the respective attachment part. The respective attachment part may,of course, also be composed of a plurality of bodies for this purpose.

The invention has been described in detail with particular reference topreferred embodiments thereof and examples, but it will be understoodthat variations and modifications can be effected within the spirit andscope of the invention covered by the claims which may include thephrase “at least one of A, B and C” or a similar phrase as analternative expression that means one or more of A, B and C may be used,contrary to the holding in Superguide v. DIRECTV, 69 USPQ2d 1865 (Fed.Cir. 2004).

1. A machine having a rotor mounted on a rotor shaft to rotate about arotation axis, comprising: a rotor external housing which is attached tothe rotor shaft; a winding comprising a winding former and a windingthat is to be cooled, the external housing surrounding the windingformer and the winding that is to be cooled; a device which transmitstorque between the winding former and the rotor shaft, the device beingprovided for at least one end of the winding former, the devicecomprising: a pair of metal flange attachment parts, each having amating surface; and a rotationally symmetrical composite body composedof a plastic reinforced with fiber material, to connect the metalflanges, wherein the composite body comprises side parts and a centerpart integrally located between the side part, the side parts eachhaving a funnel portion that widens away from the winding former, thecenter part being formed as a hollow cylinder, at least a portion of thecenter part extending freely between the attachment parts, wherein theside parts each have a corrugated portion with a corrugated shape whenseen in the circumferential direction, the center part is largelyuncorrugated, the side parts are connected respectively, in aninterlocking and power-transmitting manner, to the metal flangeattachment parts, and each side part of the composite body is detachablypressed against the mating surface of one attachment part, the matingsurfaces of the attachment parts each having a shape that matches thatof the respective side part; and a compression ring body detachablyconnected to each attachment part in a power-transmitting manner, eachcompression ring body having a pressing surface with a shape matchingthat of a corresponding side part.
 2. The machine as claimed in claim 1,wherein the side parts having a uniform corrugated shape when seen inthe circumferential direction.
 3. The machine as claimed in claim 1,wherein the side parts have a corrugated shape in the form of a sinewave or a circular arc when seen in the circumferential direction. 4.The machine as claimed in claim 1, wherein the funnel portion of eachside part has the corrugated shape.
 5. The machine as claimed in claim1, wherein the side parts of the composite body each have an end sectionin the form of a hollow cylinder.
 6. The machine as claimed in claim 5,wherein each end section has a corrugated shape.
 7. The machine asclaimed in claim 1, wherein outer portions of the center part of thecomposite body are pressed in an interlocking, power-transmitting manneragainst corresponding attachment parts by a respective compression ringbody.
 8. The machine as claimed in claim 1, wherein the side parts arejoined to the center part at respective junctions, and at least themajority of fibers in the fiber material extend without interruptionover the junctions between the side parts and the center part.
 9. Themachine as claimed in claim 1, wherein the fiber material of thecomposite body is formed of glass fibers or carbon fibers.
 10. Themachine as claimed in claim 1, wherein the flange-like attachment partsare each provided with an end tooth system, which can engage in acorresponding tooth system on the associated part of the winding formeror of the side housing part of the rotor external housing which isconnected to the rotor shaft part.
 11. The machine as claimed in claim10, wherein the tooth system is designed to be self-centering.
 12. Themachine as claimed in claim 1, wherein the flange-like attachment partsare made of a steel.
 13. The machine as claimed in claim 1, wherein theconnection between each compression ring body and the respectiveattachment part is a screw connection.
 14. The machine as claimed inclaim 1, wherein the winding to be cooled has conductors containingmetallic low-T_(c) superconductor material or metal-oxide high-T_(c)superconductor material.
 15. The machine as claimed in claim 1, whereinthe winding former is surrounded by a vacuum.
 16. The machine as claimedin claim 1, wherein the center part of the composite body is completelyuncorrugated.